Droppers are clothes hangers that actually drop all your clothes. You hang your prized frock, shirt or leather thongs up - only to find them on the closet floor.
'Droppers' are an example of the stealth technology employed by manufacturers of blood pressure treating drugs to increase demand for their product.

A kid who snitches on other kids that ' broke ' the rules, there by they are dropping people in it.

Tommy drew on the desk, the teacher talks to all of the class and asks who did it and says at the end of the day they can see them and tell the information. A dropper would be the one who told on Tommy.